1. Field of the Invention
This invention relates to a feed roller device of a typewriter, and particularly to a feed roller device used for reliably urging a paper to be printed against a platen of a typewriter.
2. Description of the Prior Art
The conventional feed roller device of a typewriter has been such an arrangement that there are arranged in parallel a pair of feed roller assemblies each comprising: a front feed roller row including a plurality of rollers arranged on one and the same axial line; a rear feed roller row including a plurality of rollers arranged on an axial line in parallel to that of the front feed rollers; and arms for pivotally supporting opposite ends of rotary shafts of the aforesaid feed roller rows; and resilient members are provided on the four arms pivotally supporting the rotary shafts of the feed roller rows so as to urge the aforesaid feed rollers against the platen, and the feed rollers are urged against the platen by the urging forces of the resilient members. In the feed roller device of a typewriter, in order to prevent a sheet of paper from being distorted during paper feed, it is necessary to make uniform the urging forces of the feed rollers against the platen. Since there has been provided the resilient members on the four arms, respectively, in the feed roller device of the conventional typewriter as described above, the adjustment of the feed rollers in urging force is referenced from one of the resilient members, and other three resilient members should be adjusted to have resiliencies equal in value to this resilient member, thus resulting in a troublesome work for adjustment In general, in the feed roller device of the typewriter, it is necessary that, during setting of a sheet of paper into the typewriter, the feed roller device should be set off the platen However in the feed roller device of the conventional typewriter, the mechanism for this setoff operation is one in which the respective arms are directly rocked by the working rods, thereby presenting a disadvantage of rendering to the device a complicated construction.